Glomerular Diseases Flashcards
Segmental v. Global?
Focal v. Diffuse?
part of glomerulus involved, all of glomerulus involved
some of glomeruli involved, all or almost all of the glomeruli are involved
What are the 3 parts of the filtration membrane of the glomerulus?
capillary endothelium
BM
foot processes of podocyte of glomerular capsule
Funcs. of the kidney?
Control the balance of water in the body
Control process of RBC production
Control acidity of the blood
Filter blood and pass the waste products to the bladder for excretion as urine
Control BP
Average urine physiologic protein excretion in adults? Pathologic proteinuria?
~80 mg/day
150mg or greater in 24 hours
What is the smallest plasma protein?
Albumin- filtered more readily than other proteins , can contribute to microalbuminuria
Daily excretion of more than….of protein is termed nephrotic range proteinuria
≥ 3.5 g
What is glomerular disease?
alteration of glomerular permeability- due to injury of one of the layers of filtration
-initially excess albumin w/ eventual progression to larger proteins
What are two other reasons for pathologic proteinuria?
Overflow proteinuria:
Overproduction of smaller proteins overwhelms reabsorptive ability of proximal tubule
Tubular proteinuria:
Tubulointerstitial disease leads to diminished reabsorptive capacity of the proximal tubule
How do we classify glomerular disease?
Nephritic syndrome vs. nephrotic syndrome
Primary vs. secondary
All cause some degree of glomerular damage and result in hypoalbuminemia due to urinary loss of proteins
What is the gold standard for definitive dx of glomerular disease?
BIOPSY
Describe nephritic syndrome
Inflammatory process w/ associated immunologic response leads to renal glomeruli damage
-Degree of damage is significant enough to allow blood cell passage
clinical findings in nephritic syndrome?
- edema: LE, UE, periorbital, puffy pale face
- hematuria “coca cola”
- oliguria
- HTN
- Azotemia
- rising Cr over days to month -occasional WBCs
Describe rapidly progressive glomerulonephritis
severe injury to the glomerular capillary wall, GBM and Bowman’s capsule
most severe and clinically urgent end of the nephritis spectrum
progression to renal failure in a matter of wks to mos
What are some primary nephritic syndromes?
Post Infectious Glomerulonephritis
IgA nephropathy
Henoch-Schönlein purpura
Pauci-immune glomerulonephritis (ANCA-associated)
Anti-Glomerular Basement Membrane Glomerulonephritis (Goodpasture Syndrome)
Etiology of post infectious glomerulonephritis
Group A beta hemolytic streptococci
-immune mediate glomerular injury, occurs 1-3 wks after strep infection (pharyngitis, impetigo)
Presentation of post infectious glomerulonephritis?
variable presentation
pt typically: oliguric, edematous, variably hypertensive
classic finding: coca cola urine
UA for pt with post infectious glomerulonephritis typically shows…
RBCs, red cell casts, proteinuria
Besides UA, what should you check if you suspect post infectious glomerulonephritis?
ASO (Antistreptolysin O)
will be high unless immune response has been blunted with abx tx
Px for post infectious glomerulonephritis?
good in children, less favorable for adults > prone to develop CKD
Tx for post infectious glomerulonephritis?
Supportive!
-Antihypertensives (ACE or ARB), salt restriction, diuretics PRN
NO STEROIDS- don’t improve outcomes
IgA Nephropathy is also known as…
Berger’s disease
MC primary glomerular disease world wide
What is IgA nephropathy?
IgA deposition in the glomerular mesangium > inflammatory response
-same lesion that’s seen in Henoch-Schonlein purpura
Epidemiology of IgA nephropathy?
MCly seen in children and young adults
M > F
Presentation of IgA nephropathy?
usually follows a URI or GI infection
coca cola urine 1-3 days after illness onset
Labs for pt with IgA nephropathy typically reveal…
Labs consistent with nephritic syndrome
hematuria, proteinuria, increased IgA levels, complement levels normal
Px for pts with IgA nephropathy? What is a favorable prognostic indicator?
1/3 > spontaneous remission
1/3 > CKD
1/3 chronic microscopic hematuria and stable Sr Cr
proteinuria <1g/d
Tx for IgA nephropathy?
corticosteroids if proteinuria 1.0-3.5g/day
ACE or ARBs if severe proteinuria
Target BP <130/80
What is Henoch-Schonlein purpura?
systemic small vessel vasculitis assoc. with IgA deposition in vessel walls, similar to IgA nephropathy
Epidemiology of Henoch-Schonlein purpura?
MC in children
assoc. with an inciting infection such as a group A streptococcus
Classic presentation of Henoch-Schonlein purpura?
palpable purpura in the LE and buttock area with arthralgias and abd sxs (N, colic, melena)
Decrease in GFR is common with a nephritic presentation but some may incur enough damage that leads to nephrotic presentation
Tx for Henoch-Schonlein purpura?
no definitive tx
but plasma exchange and DMARDs (anti rheumatic drugs) may help
What is Pauci-immune glomerulonephritis (ANCA-associated) seen with?
small vessel vasculitides
-Wegner granulomatosis
- churg-Strauss disease
- mircoscopic polyaniitis/polyarteritis
S/S of pauci-immune glomerulonephritis?
those of a systemic inflammatory disease
- fever, malaise, weight loss, purpura
- 90% of those with Wegner granulomatosis have respiratory tract sxs with nodular lesions that can bleed
Labs for pauci-immune glomerulonephritis?
ANCA +
UA: hematuria and proteinuria
Proteinuria:
- Nephritic range?
- Nephrotic range?
2g/day
4g/day
Tx for pauci-immune glomerulonephritis?
high dose corticosteroids!
DMARDs
with tx: 75% remission
without: poor px
Describe Goodpasture syndrome (Anti-glomerular BM glomerulonephritis)
Glomerulonephritis + pulmonary hemorrhage (2/3)
basement membrane injury from anti-GBM antibodies
Peak incidence for goodpasture syndrome occurs in which age range?
2nd-3rd decade
6th-7th decade
S/S of goodpasture syndrome?
onset follows URI in most cases
hemoptysis and dyspnea
RPGN
Work up for goodpasture syndrome?
Anti-GBM abs in 90% of pts
Sputum: hemosiderin-laden macrophages
CXR: pulmonary infiltrates
Tx for goodpasture syndrome?
Plasma exchange therapy
Immunosuppressive drugs > prevents formation of new abs and controls inflammatory response
-corticosteroids, DMARDs
Describe Nephrotic syndrome
significantly increased basement membrane
Essential components for dx of nephrotic syndrome?
Urine protein excretion ≥ 3.5 g per 24 hours
Hypoalbuminemia (serum albumin < 3 g/dL)
Bland urinary sediment: oval fat bodies may be seen
Peripheral edema
Hyperlipidemia
S/S of nephrotic syndrome?
peripheral edema*
dyspnea (pulmonary edema, pleural effusions)
UA in pt with nephrotic syndrome may reveal…
Blood chemistries…
proteinuria from an alteration of the GBM, oval fat bodies > assoc. with marked hyperlipidemia
decreased serum albumin, hyperlipidemia in >50% with early nephrotic syndrome
In patients with nephrotic syndrome, loss of binding proteins in the urine can cause them to be deficient in…
Vitamin D, Zinc, and Copper
Tx for nephrotic syndrome
Increase dietary protein
Edema: salt restriction, Thiazide and loop diuretics used frequently
Tx hyperlipidemia: mod/high dose Statin
Those with serum albumin <2 can become hypercoagulable, may need anticaogs
What are some nephrotic syndromes?
Minimal Change Disease
Membranous nephropathy
Focal Segmental
Glomerulosclerosis (FSGS)
Describe minimal change disease
increases level of glomerular permeability, foot process effacement
mainly seen in children
S/S of minimal change disease?
classic nephrotic syndrome:
peripheral edema, massive proteinuria, hypoalbuminemia, hyperlipidemia
Tx for minimal change disease?
oral corticosteroids with prolonged taper, relapse is common upon discontinuation of steroids
progression to ESRD is rare
MC cause of primary nephrotic syndrome in adults?
membranous nephropathy
Describe membranous nephropathy
Idiopathic immune mediated glomerulopathy
Immune complex deposition in glomerular capillary walls results in increased permeability
Clinical presentation for membranous nephropathy?
Clinical presentation is variable:
- Asymptomatic
- Edema w/ frothy urine
- High incidence of venous thromboembolism
labs range from subnephrotic to classic nephrotic
Tx for membranous nephropathy
targets reduction of urine protein levels with ACE or ARB if BP > 125/75
corticosteroid therapy initiated in pts with failure to improve with 6 months of conservative care
Describe focal segmental glomerulosclerosis (FSGS)
Increased permeability due to podocyte injury
-primary > mostly idiopathic
-secondary > obesity, hypertension, chronic urinary reflux, HIV infection, analgesic or bisphosphonate exposure
Initial clinical presentation for focal segmental glomerulosclerosis?
proteinuria
-80% of children and 50% of adults present with overt nephrotic syndrome
Tx for focal segmental glomerulosclerosis?
Diuretics for edema
ACE/ARB to reduce proteinuria & HTN
Statins for hyperlipidemia
Corticosteroids for those w/ primary cause & overt nephrotic syndrome: high dose then taper
